Automatic slack adjuster



June 7, 1932. P. B. CAMP AUTOMATIC sLAoK ADJUSTER,

m .Q 1 -lwv Rw, l 1 um. hh w WJQNN MJ M m Nw n @N Nw @N June 7, 1932. P. B. cAMP AUTOMATIC SLACK ADJUSTER Filed May 18, 1922i 5 Sheets-Sheet 2 June 7, 1932. P. "B, CAMP AUTOMATIC sLAc'K ADJUSTER Filed May 18, w28' 5 S'heetss'heet Patented June 7, 1932 UNHTED PERCY B. CAMP, F MAYWOOD, ILLINOIS, ASSIGNOR TO UNIVERSAL DRAFT GEAR ATTACHMENT CO., A CORPORATION OF ILLINOIS AUTOMATLVC SLI-CK ADJUSTER Application led May 18,

This invention relates to railway brakes and more particularly to devices for automatically adjusting the brake operating mechanism.

The principal obj ect of the invention is the provision of new and improved means for automatically taking up the slack in brake operating mechanism and for automatically releasing and properly adjusting said mechanism when new brake shoes are substituted for those that are badly worn.

A further object of the invention is the provision of a new and improved brake operating mechanism that is cheap to manufacture, easily assembled, composed of few moving parts, that is eflicient and automatic in operation, and that is not likely to become broken or get out of order.

Other and further objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a plan view of a brake operating mechanism for railway cars, shown more or less diagrammatically-and showing my invention in position thereon;

Fig. 2 is a section on line 2 2 of Fig. l;

Fig. 3 is a section on line 3--3 of Fig. 2, with parts broken away;

Fig. 4 is ahorizontal section of the takeup device, with parts broken away;

Fig. 5 is a section on line 5 5 of Fig. 4;

Fig. 6 is a plan view illustrating the takeup device;

Fig. is a section on line 7 7 of Fig. 6;

Fig. 8 is an end elevation of an anchoring device;

Fig. 9 is a plan thereof, with parts broken away; and l Fig. 10 is a side elevation of the trip member.

In the construction of railway brake operating mechanism, it is desirable that the mechanism be so adjusted that the levers eX- tend normal to the direction of the applied force when the brakes are set so that the levers will operate at their maximum efficiency.

In order to maintain the brake operatingY mechanism at its maximum eiiiciency, means must be `provided for adjusting said mecha- 1928. Serial No. 278,869.

nism as the parts wear. The brake shoes, for instance, wear rapidly, and hence the mechanism must be adjusted from time to time to compensate for this wear.

Tt is the common practice to provide both power and manually operated means for operating the brakes on railway cars, especially on railway passenger cars. It has been proposed to provide means for automatically taking up the slack developed in the brake operating mechanism, but in such devices the adjustment of the mechanism to accommodate the insertion of new or unworn shoes has to be made by hand. This is objectionable because it not only takes time, but either through mistake or carelessness, the adjustment may not be properly made.

The present invention seeks to eliminate this dificulty by the provision of means for automatically, releasably adjusting the mechanism when new shoes are inserted, as well as automatically taking up the slack when the shoes become worn.

In the form of the device selected to illustrate one embodiment of the invention, the device is shown in connection with the hand brake operating mechanism.

Referring now to the drawings, the reference character 10 designates generally the foundation brake gear for a railway car. This gear is of the usual or any well known construction and comprises the Vair brake cylinder 11; the live cylinder lever 12 connected to the piston 13 of the cylinder 11; and the dead cylinder lever 14 pivotally connected to the cylinder I1 by any suitable means, as the conventional automatic take up device. 15. This device automatically takes up the slack in the brake mechanism. A disclosure of one form of this device may be foiund on page 841 of the Car Builders Encyclopedia, 1922, published by Simmons- Boardman Publishing Co., and need not be herein described.

The levers 12 and 14 are connected together in the usual manner by the link or rod 16.

Since the operating mechanisms at each end of the car are substantial duplicates, only one need be described. 'Y

rThe live cylinder lever 12 is connected to an equalizing `lever 17 by means of a suitable connecting rod 18 having the sliding joint 18atherein for permitting the hand brake at one end of the car to apply the brakes to one truck without applying them to the other, as is usual in such constructions. The cqualizing` lever 17 has one end connected to the live-truck lever 19, as by means of a top connecting rod 21 at one side of the car and its other end connected to a similar lever at the other side of the car. The lever 19 is adapted to apply the brakes 22 to the wheels 23 through the dead truck lever 2O and the connecting rod in the usual manner.

Suitable means are also provided at each end of the car for manually applying the brakes. As shown, this mechanism conipriscs the conventional brake stall 24, which is connected to the lever 25 by a suitable flexible connecting member 26, the brake rod 59 and including the novel slack take-up device 31. The lever 25 is fulcrumed at 27 and is pivoted to the connecting rod 18 as at 23, whereby when the flexible connecting member 26 is wound on the stall, the lever 25 will be moverL to operate the connecting rod 13 for applying the brakes at one end ot the car. Likewise, by rotating the brake staff 29 the brakes. may be operated at the other end of the car.

rlhe slack take-up device 31 comprises a yoke 32 and casing 37, Fig. 6, which are slidably mounted beneath the car by any appropriate means. As shown, the device is provided with lateral extensions 38 and 39 which slidably engage the supports 33 and 34 which are carried by the angle bars 35 and 36, see l@ ig. 6, secured beneath the car.

rEhe yoke 32 has pivoted therein a multiplying lever 41 comprising the segmental statia arm 42 and the brake arm 43. The stati arm is connected to the brake staff by the oonnecting member 44 each end of which is flexible, one end being connected to the arm 42 and trained about the segmental portion thereof, and the other end to the winding drum of the brake sta in the usual manner. A flexible member, as the chain 45, connects the brake arm 43 with an anchor member 46. The construction and operation of the multiplyinglever mechanism are disclosed in patent to William H. Clegg, No. 1,558,840, issued October 27, 1925, and need not be further described except to state that it is so constructed that upon the initial turning of the brake stad at the end of the car the arm 42 will rotate rapidly to bring the brake shoes into contact with the wheels, and

on further movement the segmental arm 42 having been moved to a position substantially normal to the member 44, will apply the brakes with a powerful leverage.

The mechanism is normally held in retracted or released position by a spring 61 contained within a cylinder 62 rigidly connected to the device 31 and movable therewith, see Fig. 4. A rod 63 rigidly connected to an anchor member 46 has one end extending into said cylinder and provided with a spring seat 64 which engages the end of said spring, and is adapted to compress the spring when the device moves toward the right, as seen in Fig. 4, for applying the brakes by manually operating the brake shaft 24.

The anchor member 46 is rigidly secured in position in any convenient manner, as by being connected to the flanges of the angle bars or supports 33 and 34 as shown ingFig. 6. This member is provided with a sleeve 47 having its longitudinally extending opening 5() in the form of slots intersecting at right angles for receiving the links of the anchoring member 45. The anchor chain is connected to the anchor member by a pin 48 which extends through a link of the chain in any one of a pluralitv of holes through said sleeve. In order to provide means for shortening the chain less than the distance between two links, a plurality of sets of openings through the sleeve may be provided. As shown, a plurality of holes 49 extend diagonally through the sleeve from one side thereof and one or more holes 51 extend downwardly and laterally through the sleeve from the other side thereof. The holes 49 and 51 are spaced longitudinally of the sleeve axis a distance less than the distance between two links whereby a line adjustment may be made to properly position the multiplying lever.

ln applying air brakes, it is desirable that the piston have a travel of a definite or predetermined distance, usually o about eight inches. The wear on the parts, especially on the brake shoes will increase this travel and materially reduce the eliiciency of the mechanism unless means be provided for compensating for this wear. The slack caused by the wear of the shoes and other parts is usually taken up by an automatically operated device, indicated at 15, Fig. 1, by moving the ulcrum of lever 14, Fig. 1, to the left This in turn draws the equalizer levers 17 toward the cylinder, moves the lever 25 and produces slack in the flexible connection between lever 25 and staff 24. This would require a continually increasir(Y amount of chain to be wound on stall 24 and to correct this condition is the Jfunction of the slack take-up device which will now be described.

Slidably mounted within the casing 37 is a ratchet bar 52 formed on or attached to the brake rod 59, its teeth 53 being adapted to be engaged by a holding device comprising l 'two pawls are connected together by the link ments as they move back and forth within the casing, see Fig. 5. The teeth of the bar .52 and pawl 54 positively engage for transmitting brake setting stresses from the staff 24 to the rod 59. The pawl 55 retards relative movement of the holding means 60 and ratchet bar 52 frictionally, both faces of its teeth being inclined that they may ride over the teeth of the ratchet bar in either direction, but with greater diiiiculty when the bar 52 is moved toward the right, as shown in Fig. 5.

Upon the application of the brakes by air,

l the rack bar 52 moves to the right, carrying with it the holding device 60 because of the frictional engagement of the pawl 55. Should the brake slack be in excess of normal, the

will continue its movement after the device 60 has been arrested by the wall 69, bringing the teeth 65 into engagement with teeth of the bar more remote from its end. Upon release, the recession of the bar will be arrested as the device 60 engages the Wall 68 by reason of the readjustment which has taken place at 15. This change in relation of the rack bar 52 with the pawl 54 eliminates the slack in the hand'brake connection and thus prevents overthrow of the power multiplying lever and its consequent weakening at the end of the application movement.

The tripping action of the pawl 54 is accomplished bythe bar 58 which has an arm 71 fixed to a stop or cross piece 72, the bar being slidable with respect to the casing upon movement of the latter.

Vhile normally the pawl 54 is out of engagement with the rack bar (Fig. 5) such engagement is established as soon as the member 31 commences its movement to the right in the hand application, the tripping action of the bar 58 on the arm 57 being at once relieved, permitting the pawl 54 to drop.

This normal disengagement of parts simplifies thereadjustment of the brake system to receive a new set of shoes, to the mere restoration of the fulcrum of the lever 14 to its original position. This readjustment causes the withdrawal of the rack bar 52, bringing its forward teeth into cooperative relation with the pawl 54.

lVhen new brake shoes are to be installed, the air and hand brakes are both released (as in Fig. 5) causing the pawl 54 to be disengaged from the ratchet bar by the tripping action of thebar 58 striking the arm 57. The positive pawl 54being thus raised, the bar 52`ma-y be drawn to the .left as far as is necessary to allow for the replacement of the shoes. The holding member 60 will be properly positioned with respect to the bar 52 by the first application of the air brakes.

It is thought from the foregoing taken in connection with the accompanying drawings that the construction and operation of my device will be apparent to those skilled in the art, and that various changes in size, shape, proportion and details of construction may be made without departing from the spirit and scope of the appended claims.

I claim as my invention:

l. ln. a1 braking system for railway cars, a system of links and levers, means for operating said system by compressed air, means for manually operating said mechanism, and means for automatically adjusting said manually operated means to either increase or decrease slack.

2. In a brake mechanism, the combination of a foundation brake orear, a brake cylinderl for operating the foundation brake gear, and a hand brake for operating the foundation brake gear including a rack moving when the air pressure is applied, a pawl cooperat-V ing with the rack upon excess movement of the rack by the air pressure to automatically adjust the hand brake to compensate for slack and to accommodate the insertion of new shoes. i

3. In combination, a foundation brake gear,'power means for operating said gear, manually operated mechanism for operating said gear, and means for automatically adjusting said mechanism for compensating for the wear of the brake slices and for accommodating the insertion of new brake shoes.

4. In combination, a foundation brake gear, power means for operating said gear, manually operated mechanism for operating said gear, and means for automatically adjusting said mechanism when new brake shoes are applied so as not to interfere with the normal operatio-n of said power means.

5. In combination, a plurality of brakes, handmechanism for operating said brakes,

`automatic means for taking up slack in said mechanism for compensating for wear of the brake shoes and for releasing said mechanism to accommodate the insertion of new brake shoes and for maintaining said shoes at a uniform distance from the wheels in released position.

6. In combination, a foundation brake gear, power means for operating said gear, means for manually operating said gear, said means comprising a brake staff, and a iiexible connection between said staff and said gear, said flexible connection including means for automatically lengthening said connesl tion when new brake shoes are inserted.

7. In a brake operating mechanism, a casing, a slack adjuster slidably mounted Within said casing, said adjuster comprising a ratchet bar, a holding device on said bar having means Jfor releasably engaging said bar, a pawl for holding said bar from moving in one direction through said casing, and means for automatically releasing said pavvl for adjusting said mechanism -for accommodating 10 the insertion of new brake shoes.

8. In a brake operating mechanism, a casing, a slack adjuster slidably mounted Within said casing, said adjuster comprising a ratchet bar slidably mounted in the front 15 Wall of said casing, a holding member yieldably engaging the ratchets of said bar, a

paWl member for holding said bar from moving in one direction relative to said casing, a

link for pivotally connecting said members together, an arm rigidly connected to said link, a trip member slidably mounted in said casing, and means for engaging said trip member for causing said link to disengage said pawl member from said ratchet bar upon the release of the brakes.

9. In a brake mechanism, a foundation brake gear, a hand brake mechanism operatively connected to the gear, means associated With the foundation brake gear to take up excess slack, and means operable from the foundation brake gear including slack ad justing means to automatically adjust the hand brake mechanism by either increasing or decreasing slack.

10. In a brake mechanism, a foundation brake gear, means for operating the gear, and a slack adjuster associated therewith including paWl and ratchet mechanism and releasing means, adapted to automaticallyadjust itself by either increasing or decreasing the slack to provide proper brake shoe clearance at all times when the foundation brake gear is in adjustment.

1l. In a slack adjuster, a casing, a rack bar, means for allowing the bar to shift in either direction through the casing to provide proper brake shoe clearance, and means for holding the bar in adjusted position.

l2. In a device of' the class described, a casing, a rack bar slidable through the casing, holding means in frictional engagement with the bar, and a paWl normally disengaged from the bar but engageable therewith upon application or the brakes.

In testimony whereof I aiiix my signature.

PERCY B. CAMP. 

